Watch: Kate Winslet explores her bond with James Cameron since Titanic
Winslet made infamous comments about her director after the fraught shoot on the 1997 movie, saying in an interview that he "has a temper like you wouldn't believe" and she "would only work for Jim Cameron again for a lot of money".
More than two decades later though, director and star were on set together again, with Winslet taking on the role of Na'vi warrior Ronal in Avatar: The Way of Water.
"I think we're just older, wiser, different people. Creatively, hopefully, I've gone away and learned a lot of things and he has, for sure, evolved enormously as a director and as a person," Winslet told Yahoo UK.
She added: "He's driven and determined the way he always was but, my god, he's just such a genius. To watch him at work and to see the detail that goes into it, he's really running the show.
"He's the only one who ultimately knows what needs to happen in order to achieve his vision. And he's always right.
"What's lovely is that, when he isn't right, now he will say: 'That was kind of a mistake. That was never really gonna work, but I just wanted to try it to see and yes I was wrong'.
"So it's really kind of reassuring to know that he is able to say 'I could've had a better idea for that thing'. Any of us are like that, so I really appreciated that about Jim. It was fantastic."
Winslet's character in the movie is Ronal, wife of the leader of the Metkayina Na'vi clan, which takes in protagonists Jake and Neytiri as well as their family as refugees.
Ronal is pregnant during the film, which Winslet describes as being a hugely important facet of the character as "pregnant women are capable of doing a lot".
She added: "People don't always necessarily think that. Jim knows what women are capable of, and is totally in awe of it.
"I love that he included that in his film because he clearly has so much admiration for the physical ability of pregnant women. It was a wonderful thing to be a part of."
With her previous work for Cameron also being water-based, her role in the Avatar sequel raises the spectre of a certain ocean scene from 1997 — and a notorious chunk of door.
"It's funny, the door seems to have had a resurgence over the last few years. I don't know why," said Winslet.
She added: "People seem to be doing all kinds of experiments as to whether or not they could've really fit on the door.
"It's hilarious. It's one of those unanswerable questions. We'll have to just go back there again and see if we could really both get on that door eventually."
But on this occasion, Winslet's underwater survival skills have become legendary. During one sequence, she held her breath underwater for seven minutes and 14 seconds, breaking a record set by Tom Cruise.
Winslet explained that she was "surprised at how well I could actually do it", but always thought it was a skill she could learn given the chance.
She said: "I knew going into it that it was something I was going to be really at ease with, and I knew there was the potential that I could maybe get quite good at it just because I was never afraid.
"I was able to relax myself enough to be able to hold my breath for quite long periods of time sort of from the outset. But when I did that big breath-hold, I couldn't believe it. I was very proud of myself and I was amazed that I did that."
Avatar: The Way of Water will be released into cinemas and IMAX on 16 December.
Watch: Trailer for Avatar: The Way of Water